The fifth Black Widowers collection has stories from 1984 to 1989, 11 appearing originally in Ellery Queen's Mystery Magazine . Asimov again uses a real-life New York dining club as model for the Widowers. In every story a dinner guest is asked, "How do you justify your existence?" The guests--graduate student, government spook, bookseller, plumber et al.--dispose of the question, and then pose a puzzle for the Widowers to chew over--over and over. Invariably, after the chewing, the deferential, cerebral waiter Henry, also a Widower, comes up with the solution. Said solution turns on some piece of arcana--Bermuda traffic rules, the element with the most syllables--that most readers won't know or care about. Each story is less than two dozen pages, a relief because the writing is like unbuttered, unsalted popcorn: harmless but not satisfying unless you're already addicted. Asimov assures us the Black Widowers "will continue as long as I do." Long life anyway, Dr. A.